OBJECTIVE: To characterize the neonatal and maternal outcomes of type 2 diabetic patients as compared with type 1 diabetic patients and nondiabetic controls.

STUDY DESIGN: We performed a retrospective cohort study reviewing perinatal outcomes of type 1 and type 2 diabetic patients and nondiabetic controls from July 2000 to August 2006. Analysis of variance, t testing and c2 analysis were used to compare groups. Post hoc power analysis indicated 80% power was necessary to detect a 15% difference in composite poor neonatal outcomes.

RESULTS: A total of 64 type 2 and 64 type 1 diabetic patients were compared with 256 controls. Type 1 diabetic patients had higher incidences of composite poor neonatal outcome and congenital anomalies than did type 2 diabetic and control patients. Both diabetic groups had similarly higher incidences of cesarean delivery, preeclampsia, preterm delivery, polyhydramnios and macrosomia than did controls.

CONCLUSION: Type 2 diabetic patients have a decreased incidence of adverse neonatal outcomes when compared with that of type 1 diabetic patients. No difference was observed between the diabetic groups in the incidence of a majority of the adverse maternal outcomes examined, however both diabetic groups had overall worse outcomes that did nondiabetic controls.